1. Field of the Invention
The present invention relates to a package starting control device for determining a moment and a sequence of starting a package that corresponds to an individual wavelength to be a subject of wavelength division multiplexing in a wavelength division multiplex transmission device.
2. Description of the Related Art
Since a wavelength division multiplex transmission system commonly uses an optical fiber having a low loss even in a wide band with asynchrony at plural wavelengths so that the wavelength division multiplex transmission system is suitable for transmission of various digital and analog signals having a large capacity and for a flexible construction of a network, it is widely applied to many basic transmission lines.
FIG. 6 is a diagram illustrating an example of a structure of an optical transmission system to which a wavelength division multiplex transmission system is applied.
In FIG. 6, WDM transmission devices 30-1 and 30-2 are connected to one end and the other end of a full duplex optical transmission line 31, respectively. Client transmission devices 30C-11 to 30C-1n and client transmission devices 30C-21 to 30C-2n are connected to the above-mentioned WDM transmission devices 30-1 and 30-2, respectively.
In the WDM transmission device 30-1, transponder packages (TRPN) 32-11 to 32-1n are connected to the client transmission devices 30C-11 to 30C-1n. Optical output terminals of the transponder packages 32-11 to 32-1n are connected to corresponding input terminals of a wavelength division multiplexer (MUX) 33-1, and an output terminal of the wavelength division multiplexing unit 33-1 is connected to one end of a downstream link of an optical transmission line 31 through a postpackage (PST) 34-1. One end of an upstream link of the optical transmission line 31 is connected to an optical input terminal of a prepackage (PRE) 35-1, and an output terminal of the prepackage 35-1 is connected to an input terminal of a wavelength division demultiplexer (DMUX) 36-1. First to n-th output terminals of the wavelength division demultiplexer 36-1 are connected to optical input terminals of the transponder packages 32-11 to 32-1n, respectively. In addition, control terminals of the transponder packages 32-11 to 32-1n, the wavelength division multiplexer 33-1, the postpackage 34-1, the prepackage 35-1, and the wavelength division demultiplexer 36-1 are connected to a bus terminal of a processor 38-1 (CPU) through an internal bus 37-1.
In addition, a structure of the WDM transmission device 30-2 is the same as that of the WDM transmission device 30-1. Therefore, in the following description, corresponding constituent elements are denoted by the same reference numeral to which a first appended number ‘2’ is attached and the description thereof is omitted.
In addition, in the following description, on common matters of the WDM transmission devices 30-1 and 30-2, their descriptions will be made using reference numerals to which an appended character ‘C’ corresponding to any one of first appended numbers ‘1’ and ‘2’ is attached as their first appended character.
In addition, in the following description, on common matters of transponder packages 32-C1 to 32-Cn, their descriptions will be made using reference numerals to which an appended character ‘c’ corresponding to any one of second appended numbers ‘1’ to ‘n’ is attached as their second appended character.
In the optical transmission system having the above-mentioned structure, for example, a processor 38-C instructs a TRPN 32-Cc to start in accordance with a request (hereinafter, referred to as ‘an initial setting command’) instructed by an operator through a terminal device (not shown) in a state in which the TRPN 32-Cc, a postpackage 34-C, and a prepackage 35-C are respectively mounted on a WDM transmission device 30-C.
The TRPN 32-Cc starts in accordance with the request and performs an initial setting (FIG. 7(1)) suitable for office data and each configuration of hardware. After that, the TRPN 32-Cc waits in a state in which the optical signal can be output (hereinafter, referred to as a shutdown state) (FIG. 7(2)).
In addition, the processor 38-C waits for a command (hereinafter, ‘a shutdown release command’) instructed by the operator and transmits ‘the shutdown release command’ to the TRPN 32-Cc, similarly to the above-mentioned request to the TRPN 32-Cc (FIG. 7(3)).
The TRPN 32-Cc initiates the driving of a built-in optical module in accordance with the transmitted ‘shutdown release command’ as described above (FIG. 7(4)).
The transponder package 32-Cc converts a signal supplied from a client transmission device 30C-Cc into an optical signal, to which wavelength division multiplexing can be made, through an electric-optic conversion. A wavelength division multiplexer 33-C wavelength division multiplexes the optical signals having n different wavelengths output by the transponder packages 32-C1 to 32-Cn as a result of the electric-optic conversion to thus produce WDM signals. The postpackage 34-C amplifies the WDM signals to output them to the downstream link of the optical transmission line 31.
The prepackage 35-C amplifies the WDM signals input through the upstream link of the optical transmission line 31 to supply them to a wavelength division demultiplexer 36-C. The wavelength division demultiplexer 36-C subjects the WDM signal to a wavelength division demultiplexing to obtain n optical signals having different wavelengths. The transponder package 32-Cc subjects a corresponding optical signal among the n optical signals to the optic-electric conversion to generate a signal, and delivers it to the client transmission device 30C-Cc.
In addition, in a state in which, for example, the transponder package 32-C1 is not mounted on the WDM transmission device among the transponder packages 32-C1 to 32-Cn, and the postpackage 34-C and the prepackage 35-C normally operate together with the transponder packages 32-C2 to 32-Cn other than transponder package 32-C1, when the transponder package 32-C1 (herein, it is assumed that the transponderpackage 32-C1 can be hot-plugged on a WDM transmission device 30-C through a connector) is newly mounted on the WDM transmission device 30-C, each unit operates as follows.
The processor 38-C instructs the transponder package 32-C1 to start in accordance with ‘an initial setting command’ instructed by an operator in a state in which the transponderpackage 32-C1 is mounted on the WDM transmission device 30-C, as described above.
In addition, the processor 38-C transmits ‘the shutdown release command’ instructed by the operator to the transponder package 32-C1, and transmits a message (hereinafter, referred as to a wavelength number increase/decrease setting request) indicating the purport to the postpackage 34-C and the prepackage 35-C.
The transponder package 32-C1 starts a normal operation accompanying the output of an optical signal (an optical signal modulated with the signal supplied from the client transmission device 30C-C1) having a predetermined wavelength of λ1 in accordance with ‘the shutdown release command’.
When the postpackage 34-C identifies ‘the wavelength number increase/decrease setting request’, the postpackage 34-C notifies the other WDM transmission device connected to the WDM transmission device 30-C, through the downstream (upstream) link of the optical transmission line 31, of [the addition of the wavelength λ1 (herein, it is assumed that the wavelength λ1 is identified as information included in ‘the wavelength number increase/decrease setting request’) in a wavelength band].
The postpackage 34-C delivers to the processor 38-C a response (hereinafter, referred to as ‘a wavelength number increase/decrease response’, and it is assumed that the response is received through the upstream (downstream) link of the optical transmission line) to the notification of the addition of the wavelength λ1 from the other WDM transmission device.
The processor 38-C transmits ‘the wavelength number increase/decrease response’ to the transponder package 32-C1, and at the time of identifying ‘the wavelength number increase/decrease response’, the transponder package 32-C1 completes the wavelength number increase/decrease setting according to the increase of the wavelength number (multiplicity) due to the addition of the optical signal having the wavelength λ1.
In addition, an example of a conventional art related to the present invention is disclosed in Patent Document 1 described below. According to Patent Document 1, a method for controlling an optical attenuator in an optical amplifier that, in a wavelength-multiplexed optical network having the optical amplifier, an amplifying unit for amplifying the wavelength-multiplexed optical signal has a gain held constantly, attenuation of a variable optical attenuator set in an optical amplifier used for adjusting a level of the wavelength-multiplexed optical signal is generally set to have a fixed value, the optical attenuation is adjusted such that only when wavelength number information functioning as control information is input, a value of an optical output monitor at a specific location at which the set value of the variable optical attenuator reflects the optical attenuation of the optical attenuator becomes a predetermined value represented from the wavelength number information, and the optical attenuation is held at the state obtained by the adjustment until a next wavelength number information is input, is disclosed.
[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2002-246986
However, in the above-mentioned conventional example, the wavelength number increase/decrease setting according to the addition/removal of the transponder package is performed for each transponder package to be an subject of the addition/removal in accordance with ‘the initial setting command’ and ‘the shutdown release command’ instructed by an operator, and the operator must determine a moment issuing ‘the initial setting command’ and ‘the shutdown release command’ sufficiently in consideration of characteristics of the corresponding transponder package as well as a structure of a network including the WDM transmission device 30-C and the optical transmission line 31.
In addition, since there exist a variation in the characteristics (including a warming-up time of from several tens of seconds to several minutes required for the optical module for generating the optical signal to normally operate) of the transponder package to be a subject of the addition or removal, a sufficient waiting time must be ensured such that the transponder package can suitably respond ((5) of FIG. 7).
As a result, a manipulation which is performed by the operator taking charge of a work related to the maintenance or operation as described above becomes complicated as the number of the added or exchanged transponder packages increases, and the long time is necessary to ensure the waiting time.